Device for determining female fertility periods

ABSTRACT

A two-part slide rule type device having in one part and on one line successive days of each two successive months throughout the year, the other part being divided into sections of greatest and less fertility. The second part is superimposed on the first with its beginning at the date of the first day of menstruation, and the divisions of the second part then indicate the dates of the periods of greatest and less fertility.

United States Patent [72] Inventor Ernesto F. Colon Mayaguez, P.R.

[21] Appl. No. 873,331

[22] Filed Nov. 3, 1969 [45] Patented Dec. 7, 1971 [73] Assignee The Government of the Commonwealth of Puerto Rico Primary ExaminerStephen .1. Tomsky Al!0rneyScrivener, Parker, Scrivener and Clarke [541 FEMALE ABSTRACT: A two-part slide rule type device having in one 2 Cl i 2 D i E part and on one line successive days of each two successive months throughout the year, the other part being divided into [52] U.S.Cl .3. 235/85 FC, sections of greatest and less fertility The second part su- 235/89 R perimposed on the first with its beginning at the date of the [51] Int. Cl G06c 3/00 first day of menstruation, and the divisions of the second part [50] Field of Search 235/85 RC, then indicate the dates of the periods of greatest and less fer- 89; 40/107. 109, 110, 111 tility.

8 l0 2 4 16 u w s I 1 FIRST on MENSTRUATION 1 NEXT MONTH JAN! 2 3 4 5 6 r F) 9 1011i I213 41515171819202122232425262725293031I 2 3 4 5 6 7 8 91011I21314151617181920212223242526272829 FEBI 3 5 7 9 11 15 15 I7 19 21 23 27 29 2 3 4 5 G 7 B 910111913141516171819 202122232425262728293051 MAR 5 5 7 9 l1 l3 I5 17 I9 21 23 25 27 29 3| 1 2 3 4 5 5 7 B 910111213141516171819 2021222324252627282950 APR I 3 5 7 9 ll 13 v 15 I7 19 21 23 25 27 29 I 2 3 4 5 6 7 B 910111213141516171819 21721 22232425262728830 1 MAY 3 5 7 9 11 I3 15 l7 19 2| 23 25 27 29 31 I 2 3 4 5 G 7 R 101112131415161718192021222324252627282930 N 1 3 5 1 9 11 I3 15 17 I9 21 23 25 27 29 1 2 3 4 5 S 7 8 910111213141516171819 20212223242525278293031 JUL 1 3 5 7 5 l1 l3 l5 l7 I9 21 23 25 27 29 111 2 3 4 5 S 7 B 9101112131015161710152021222324526272029 AUG I 3 5 7 9 11 13 I5 17 19 2| 23 25 27 29 31 I 2 3 4 5 6 T 8 9IOIl12131415161718192021222324252627282930 SEP 1 3 5 7 9 11 13 IE l7 19 2| 23 25 27 29 I 2 3 4 5 C 7 B 91011 1213141516171819 20212223242526212829305 OCT I 3 5 7 9 11 13 15 17 19 21 23 25 27 E 31 1 2 Z 4 5 G 8 91011I21514151517181920212223243262128830 Nov 1 3 5 T 9 11 13 15 17 I9 21 23 25 27 29 I 2 3 4 5 C 7 B 510111213141515171519 2021 2Z2324252G272Ia30 DEC 1 3 5 7 9 11 I3 15 I7 19 21 23 25 27 29 3| 1 2 3 4 5 G 7 8 910111213141515171819202122232425252728293031 USE HIS LINE FOR 28 DAYS MONTH 22232425 262725 1 2 3 4 5 6 7 8 910111213141516171819202122232425252725293031 OVULA ION OVULATION 22- 28 22 24 38 g M 34 50 5 36 M 40 42 M -LESS FERT1LE -MOST FERTILE --LES$ FERT|LE -MOST FERT|LE DEVICE FOR DETERMINING FEMALE FERTILITY PERIODS THE DRAWINGS FIG. 1 shows the device in plan view before separation of the two parts, and

FIG. 2 illustrates the use of the device.

DESCRIPTION OF THE INVENTION The device provided by the invention comprises, in its original condition as made and sold, a rectangular elongated flat device which is preferably made of cardboard or other relatively stiff material having two parts 2, 4 both of which extend from end to end of the device and are connected by a line of perforations 6 which provides a means to separate them. The part 2 is considerably wider than part 4, each being of sufficient width and length to accommodate the means described hereinafter.

The first and larger part 2 of the device is separated into two sections 8, 10 by a vertical line 12 which is disposed midway between the end edges l4, 16 of the device, the left-hand section 8 being identified by the heading "First Day Menstruation" and the right-hand section by the heading Next Month," extending across the part 2 from end edge to end edge are 12 horizontal rows which, from top to bottom, are identified by the successive months of the year by suitable wording in a vertical column 18 adjacent the left hand edge of the section, Jan. being at the top of the vertical column of months. Each horizontal line comprises the numbers of the successive days of two successive months of the year in accordance with the following table:

Jan. Jan. and Feb.

Feb. Feb. and Mar. Mar. Mar. and Apr. Apr. Apr. and May May May and June June June and July July July and Aug. Aug. Aug. and Sept. Sept. Sept. and Oct. Oct. Oct. and Nov. Nov. Nov. and Dec. Dec. Dec. and Jan.

For ease of identification and understanding in use, the first month of each line is in the section 8 and the second month is in the section 10. As illustrated in section 8, some of the day dates may be omitted for the sake of simplification, but all day dates are preferably shown, as they are in section 10.

It will be seen that each 2-month line is continuous and regular, the spacing between successive dates in each line being the same and being the same as the spacing in other lines. Further, it will be seen that the same dates of the months (e.g. the 29th) form vertical columns. This is not true of the column fonned by the last day of one month and the first day of the second succeeding month. Thus, the column indicated by reference numeral 20 includes, from top to bottom the last day of .lan., the second day of Mar. (assuming Feb. to have 29 days), the last day of Mar., the first day of May, the last day of May, the first day of July and so on. This results from the fact that the days of the second month in each line follow those of the previous month without break or separation.

Means are provided by the invention for cooperation with the date chart of the first part 2 of the device, which is described above, for determining the actual periods of greatest and least fertility, such means being incorporated in the second, smaller part 4 of the device. This part is equal in length to the larger part 2 and comprises an elongated narrow strip on ruler separably connected to part 2 by the line of perforations 6. At the left end of this part, in a position vertically below the vertical column of l 's" in part 2 which denote the first days of the months, is a mark designating the beginning of the scales of part 4, this mark being a vertical arrow 22 in the embodiment of the invention being described. Displaced to LII the right of this arrow are two successive marks 24 and 26, and it will be seen that the distance between successive marks (22 and 24, and 24 and 26) is the same as the distance between the dates of any 28-day period on part 2 of the device, for example the distance between the lst and 28th day of any month, or the distance between the 1 1th day of any month and the 28th following day, it being remembered that there are 28 days in the normal menstrual cycle.

Each of the two succeeding sections of part 4, such as the section between arrow 22 and mark 24 and between marks 24 and 26, is divided into a first part 28 which is indicated by a horizontal line beginning at the arrow marker 22 and terminating in a vertical marker 30. This section has the same length as any 7-day interval on the date chart of part 2 and therefore indicates a 7-day menstrual period, being marked with the letter M for ready identification. Following section 28 and extending from marker 30 to marker 24 is a second section 32 within which there is an ascending line 34 followed by a descending line 36, the two being of the same length. The sections 28 and 32 thus cover a 28-day period and may be termed a menstrual cycle scale. This scale is repeated to the right, beginning with the menstrual period line 38, again marked M, which is followed by the ascending and descending lines 40, 42 of equal length. 1

Means are provided for identifying on the scale of part 2 of the device the periods of greatest and least fertility during the menstrual cycle, such means being the vertically lines and identifying wording shown in FIG. 1. It is known that the most fertile period is the 10 days lying midway between the end of one menstrual period and the beginning of the next, and this period is marked off on the two sections of the chart by lines 50, 52 and identified by the wording Most Fertile. The other sections of the chart are identified by the wording Less Fertile" and it will be seen that each menstrual period section 28, 38 lies at the center or midpoint of a less fertile section.

It will be seen that the ascending and descending lines 34, 36 show increasing and decreasing fertility and that the point at which they intersect indicates the day of greatest fertility.

The use of the device is illustrated in FIG. 2, it being assumed in this figure that Jan. 1 l was the first day of menstruation. The parts 2 and 4 of the device are first separated along the line of perforations 6, and the arrow marker 22 is placed on Jan. 1 l. The scale is read to show the period of least fertility to end on Jan. 22, the period of maximum fertility to be Jan. 23 to Feb. 2, and the date of greatest fertility to be Jan. 27.

I claim:

l. A device for indicating the varying periods of female fertility, comprising a first planar part having printed thereon a vertical arrangement of horizontal rows reach of which comprises two sequential parts, the first part of each row enumerating the successive days of one of the months of the year and the successive rows showing the months of the year in sequence from Jan. to Dec., the second part of each of the successive rows showing the days of the month which follows the month the days of which are enumerated in the first part of the row, whereby each row consists of the enumerated days of a month of the year and the days of the succeeding month, and a second planar part of the device which is detachably connected to the first part and is adapted and intended to be detached therefrom for use therewith, the second part having printed thereon an elongated scale to be superimposed on any one of the month rows of the first part, the scale comprising two successive identical sections each of which is equal in length to any 28-day interval of any row of the first section of the device, each section of the scale being divided into a first part and a second part which are equal, respectively, to any 8- day and any 20-day interval of any row of the first part of the device.

2. A device according to claim 1, in which each section of the scale comprises a continuous line of which the 8-day part is horizontal and indicates the period of least fertility, and the 20-day part follows the 8-day and has ascending and descending parts of equal length to indicate periods of increasing and decreasing fertility. 

1. A device for indicating the varying periods of female fertility, comprising a first planar part having printed thereon a vertical arrangement of horizontal rows each of which comprises two sequential parts, the first part of each row enumerating the successive days of one of the months of the year anD the successive rows showing the months of the year in sequence from Jan. to Dec., the second part of each of the successive rows showing the days of the month which follows the month the days of which are enumerated in the first part of the row, whereby each row consists of the enumerated days of a month of the year and the days of the succeeding month, and a second planar part of the device which is detachably connected to the first part and is adapted and intended to be detached therefrom for use therewith, the second part having printed thereon an elongated scale to be superimposed on any one of the month rows of the first part, the scale comprising two successive identical sections each of which is equal in length to any 28-day interval of any row of the first section of the device, each section of the scale being divided into a first part and a second part which are equal, respectively, to any 8-day and any 20-day interval of any row of the first part of the device.
 2. A device according to claim 1, in which each section of the scale comprises a continuous line of which the 8-day part is horizontal and indicates the period of least fertility, and the 20-day part follows the 8-day part and has ascending and descending parts of equal length to indicate periods of increasing and decreasing fertility. 